Sum of same id in Array of object using php

Question

I want to add given_points from both array of object and show in single array of object with the help of student_id bcoz in both array of object student_id is unique.

Array
(
    [0] => stdClass Object
        (
            [student_id] => 91
            [given_points] => 8
            [bonus_points] => 2
        )

    [1] => stdClass Object
        (
            [student_id] => 91
            [given_points] => 6
            [bonus_points] => 1
        )

)
Array
(
    [0] => stdClass Object
        (
            [student_id] => 95
            [given_points] => 9
            [bonus_points] => 1
        )

    [1] => stdClass Object
        (
            [student_id] => 95
            [given_points] => 9
            [bonus_points] => 1
        )

)

Answer 1

$sum = 0;
foreach($array as $key => $value)
{
 sum+=$array[$key]['given_points'];

}

echo $sum //prints sum

Answer 2

$sum_points = 0;
$sum_student_id=0;
foreach($array as $key=>$value){
  if(isset($value->given_points))
     $sum_points += $value->given_points;
  if(isset($value->student_id))
     $sum_student_id += $value->student_id;
}
echo $sum_points;
echo $sum_student_id;

since this is an array of stdClass , use -> instead of brackets ['']

There is another way : (PHP >= 5.5)

$sum_points = array_sum(array_column($array, 'given_points'));
$sum_student_ids = array_sum(array_column($array, 'student_id'));

Answer 3

$array = [
    0 => ['student_id' => 91,
        'given_points' => 8,
        'bonus_points' => 2
    ],
    1 => ['student_id' => 91,
        'given_points' => 8,
        'bonus_points' => 2
    ],
    2 => ['student_id' => 92,
        'given_points' => 8,
        'bonus_points' => 2
    ],
    3 => ['student_id' => 93,
        'given_points' => 8,
        'bonus_points' => 2
    ]
];


foreach ($array as $row) {
    if (isset($newArray[$row['student_id']])) {
        $newArray[$row['student_id']] = $newArray[$row['student_id']] + $row['given_points'];
    } else {
        $newArray[$row['student_id']] = $row['given_points'];
    }
}

print_r($newArray);

You can try something like above code. Basically since the student_id is the unique identifier of your table and you want your logic implemented based on this then make it your new array key field.

The above code will work as many records as you have and the outputted array will look like:

Array
(
    [91] => 16
    [92] => 8
    [93] => 8
)

2 users with id 91 added, and the rest were unique users in separate array fields.